JP5051225B2 - Power distribution system, accident search / division method - Google Patents

Description

  The present invention relates to a power distribution system for performing an accident search in a power distribution system, and an accident search / division method.

  In the present age, the influence of the interruption of power supply, the so-called power failure, on daily life is immeasurable. Therefore, when an accident occurs in a part of the distribution system and a power failure occurs, the point of the accident must be identified early, the cause must be removed, and the supply of power must be resumed quickly.

  For example, when an accident involving a leakage current occurs in a 6.6 kV overhead distribution line, the power company first supplies power to the distribution system under its control at the power station or substation where the current abnormality is detected. Stop supplying. Then, the accident section is narrowed down and the power supply in the healthy section other than the accident section is resumed. After that, specific accident points within the accident section are identified. As a method for specifying such an accident section, an accident search method such as a timed expression or a distributed control expression is known.

  9 and 10 are distribution system diagrams for explaining the outline of the timed accident search method described above. In the distribution system 10 to which the timed accident search method is applied, the distribution substation 12 supplies power from the bus 14 to the high-voltage distribution network 18 via the distribution transformer 16. The high-voltage distribution network 18 includes a plurality of parallel lines (Feeders) (A) and (B) branched from the distribution transformer 16, the parallel lines (A) and (B), and the parallel lines (A). , (B) and other parallel lines are connected lines (C), (D), (E), (F), and (G).

  For example, in the distribution system 10, when an accident such as a short circuit or a ground fault occurs at a predetermined position 20 of the high-voltage distribution network 18, a protective relay such as an overcurrent protection relay or a ground fault direction relay is provided at the distribution substation 12. Operates to open the sending circuit breaker CB1, and the power supply to the parallel line A of the high-voltage distribution network 18 is stopped. When such a power failure is received, the switches A0, A1, A2 arranged on the parallel line A are automatically opened due to power loss in preparation for an accident search. FIG. 9 shows the state of the parallel line (A) after a power failure. The switches in the open state (for example, A0, A1, and A2) are outlined and closed in the closed state (for example, B0 and B1). , B2) are shown in black. All the figures shown below follow this rule.

  Then, when the sending circuit breaker CB1 of the parallel line (A) is turned on again after the lapse of a predetermined time, the switches A0, A1, A2 that are operable become sequentially (A0 → A1 → A2) from the power source side. It is thrown. When the switches are sequentially turned on in this way, when any one of the switches is turned on, here, when the switch A1 is turned on, the protective relay operates again and the delivery circuit breaker CB1 of the distribution substation 12 is opened again. A second power failure occurs.

  Here, the switch A1 immediately before the accident section 24 causes the load-side switch A2 to be kept open by the function of the time lock (open circuit). After a predetermined time has elapsed, the delivery circuit breaker CB1 is turned on again, and the switches A0, A1, A2 are turned on in order from the power supply side. However, the switches A1, A2 that are kept open are not turned on. The high-voltage distribution line on the load side from the section will be cut off. Thereafter, the switch AD on the connection line (D) is closed through a command from the control device or manual operation at the site, and power supply to the healthy section on the load side from the accident section 24 is resumed. Thus, as shown in FIG. 10, the division of the accident section 24 and the resumption of power supply to the healthy high-voltage distribution network 18 are completed.

  11 and 12 are distribution system diagrams for explaining the outline of the distributed control type accident search method. In such a power distribution system 30, when an accident occurs, the switches (switch slave stations) close to the accident section communicate with each other, and the accident section is separated by a preset algorithm (for example, Non-Patent Document 1). Yes.

  In this algorithm, for example, when a ground fault occurs at a predetermined position 20, all of the switches A <b> 1 to A <b> 3 on the power source side detect the accident. Each switch has a time difference in the transmission timing of the detection information. When the switches A1 and A2 acquire the detection information from the switch A3, the switches A1 and A2 stop transmitting their detection information, and the load on the switch A3 Know that there is an accident on the side.

Then, the communication switch AB is turned on by a preset algorithm “first turn on when switch A3 detects an accident”, and switch A4 is “second open when switch A3 detects an accident”. Released by. Finally, the switch A3 is opened after a predetermined time has elapsed. Thus, as shown in FIG. 12, the division of the accident section 24 and the resumption of power supply to the healthy high-voltage distribution network 18 are completed.
“Development of a ground-fault uninterruptible switching system” NGK, NGK Review No. 58, December 1999

  However, the timed accident search method requires two opening / closing operations of the circuit breaker in the distribution substation to separate the accident sections, and the burden caused by at least two power outages for healthy sections other than the accident sections. Will be defeated.

  In addition, in the distributed control type accident search method, a series of switches (switch unit slave stations) that operate in an interconnected manner must be arranged on the same parallel line, so that multi-division multi-linkage and system configuration change. Its extensibility with respect to the system, or their versatility becomes an issue. Further, since it is necessary to set an operation pattern in advance in the switch, complicated setting processing is performed each time the distribution line is expanded. Also, in order to avoid overloading of distribution lines, a technology to perform load division (organic distribution system switching) between parallel lines has been implemented. Therefore, it is difficult to apply it practically to the multi-division and multi-connection high-voltage distribution network in which the configuration of the distribution system is adaptively changed. It is. Further, the distributed control type accident search method does not cope with a three-phase short circuit or an overload, and there is no way to handle when the switching capacity of the switch is exceeded.

  In addition, the above-described accident search method according to the prior art has no way of knowing the line state such as voltage, current, zero phase voltage, zero phase current, harmonics, flicker, etc. at any position on the high voltage distribution network. The end of the electric wire network could not be managed. In the future, in order to ensure higher reliability of power supply and higher power quality, not only after the accident, but also by preventing the accident and preventing harmonics and flicker through partial monitoring of the high-voltage distribution network It is also desirable to do.

  The present invention has been made in view of the above-mentioned problems of conventional accident search methods, and the object of the present invention is applicable to a multi-division and multi-connection high-voltage distribution network, and is minimal in a healthy section. It is to provide a power distribution system and an accident search / division method that can quickly and reliably identify and divide an accident section by a limited power outage.

  In the present invention, in a high-voltage distribution network of multi-division and multi-connection with various interconnection configurations, an accident section is identified before a tripping circuit breaker in a distribution substation trips, and opening and closing before and after the accident section. The accident section is divided by opening / closing control only for the device. In this way, it is possible to avoid a wide range of power outages including a healthy section and to stably supply power.

In order to solve the above problems , a typical configuration of a distribution system according to the present invention includes a distribution transformer, a plurality of parallel lines (feeders) radially branched from the distribution transformer, and parallel lines A high-voltage distribution network including a connecting line that connects the two, and a sensor that is disposed on the line of the high-voltage distribution network, can open and close the line regardless of loss of power due to an accident, and can detect the line state A plurality of switches including a plurality of sensor built-in switches, a detection result acquisition unit connected to each of the plurality of sensor built-in switches, and a sensor control result unit for controlling the sensor built-in switch An information collection unit that collects the detection results obtained by the switch control device, connected to a switch control device (RTU: Remote Terminal Unit) and a plurality of switch control devices via a communication network, detection results Fault section identifying unit that identifies a fault section on the basis of the section dividing part for dividing the fault section by opening the power supply side and load side of the built-in sensor switch for fault section, and, on the type of the line distance and line distribution lines And a management server including a threshold generation unit that calculates an accident determination threshold in a plurality of sensor built-in switches and transmits the calculated accident determination thresholds to the plurality of switch control devices , and the switch control unit detects detection acquired by the switch control device characterized that you determine the presence or absence of an accident by comparing the result with the accident determination threshold. However, “radial” as used herein indicates a theoretical configuration of a power distribution system in which parallel lines extend in various directions from the power distribution transformer, and does not need to be physically formed radially. The “line state” indicates one or more electrical states of voltage, current, zero phase voltage, zero phase current, harmonics, flicker, and the like.

  Here, since the management server centrally manages all sensor built-in switches in the high-voltage distribution network via the switch control device, the fault section is identified and divided in an integrated manner before the sending circuit breaker trips. can do. Further, by providing the sensor in each sensor built-in switch, it is possible to grasp the line state such as voltage, current, zero phase voltage, zero phase current, harmonic, flicker, etc. at the installation point of each sensor built-in switch. The present invention can be applied to a multi-division and multi-connection high-voltage distribution network because the management server issues an opening / closing command to each switch control device according to the situation of the accident. It is possible to identify the accident section quickly and reliably.

  The threshold generation unit can calculate the impedance from the line distance and line type of each of the plurality of sensor built-in switches and the distribution transformer to the sensor built-in switch according to the load of the sensor built-in switch. The settling value (current value or voltage value) to be detected by the sensor built-in switch can be derived. Since the management server calculates an accident decision threshold that can be considered as an accident taking into account load fluctuations, the switch control unit of the switch control device exceeds the accident decision threshold that requires a current value or voltage value. It can be determined that an accident has occurred.

Another typical configuration of the distribution system according to the present invention includes a distribution transformer, a plurality of parallel lines radiating from the distribution transformer, and a high-voltage distribution including a connection line connecting the parallel lines. A plurality of sensor-incorporated switches provided on the lines of the electric wire network and the high-voltage distribution line network, capable of opening and closing the line and maintaining the open / closed state regardless of power loss due to an accident, and having a sensor for detecting the line state; A plurality of switch control devices each including a detection result acquisition unit that is connected to each of the plurality of sensor built-in switches and acquires a detection result of the sensor; and a switch control unit that controls the sensor built-in switch; and a plurality of switches An information collection unit that is connected to the control device via a communication network and collects the detection results acquired by the switch control device, an accident zone specification unit that specifies an accident zone based on the detection results, and the power source side of the accident zone Segment dividing unit for dividing a fault section by opening the pre-load side of the built-in sensor switch, as well as periodically collects detection results plurality of switch control unit has acquired, estimates a high probability of an accident occurring segment A management server including an accident estimation unit .

  Thus, similarly to the above, the accident section can be identified and divided in an integrated manner before the delivery breaker trips. In addition, it is possible to grasp the line condition at the installation point of each sensor built-in switch, to minimize the power outage in the healthy section, and to identify the accident section quickly and reliably.

Furthermore, in the present invention, since the detection results from the switch control device are centrally managed, there is a high probability that an accident will occur even though it has not resulted in an accident, such as a decrease in the insulation level of a covered wire or cable, tree contact, disconnection High resistance ground faults can be grasped. Therefore, it is possible not only to specify the accident section, but also to prevent the accident by predicting the occurrence of the accident and dealing with the accident prediction section in advance.

  The management server may further include a power supply restarting unit that restarts power supply from the accident section of the high-voltage distribution network to the power supply side and from the accident section to the load side.

  With such a configuration, it is possible to quickly and appropriately respond to power supply to the load-side healthy section due to the occurrence of an accident and load division of the high-voltage distribution network for overloading of the high-voltage distribution lines. In addition, the sensor provided in the sensor built-in switch can easily confirm that the power is stably supplied not only when the accident section is extracted but also after the accident.

  The sensor is one selected from the group consisting of a zero-phase current transformer (ZCT), a zero-phase voltage transformer (ZPD), a current transformer for each phase instrument (CT), and a current transformer for each phase instrument (PD) or Two or more combinations may be used. Therefore, a sensor can be comprised by the ground fault direction relay which consists of a combination of a zero phase current transformer (ZCT) and a zero phase voltage transformer (ZPD). Such a zero-phase voltage transformer (ZPD) can also be constituted by an instrument transformer (PD) for each phase. Moreover, you may use an instrument current transformer (CT) and an instrument transformer (PD) for an overcurrent relay or a voltage-current monitor.

  The zero-phase current transformer can identify a failure downstream (load side) from the sensor built-in switch, and the sensor built-in switch including the constant monitoring machine and control unit using the sensor itself. A defect or failure can also be identified. The management server can specify the section between the sensor group that detects the accident and the sensor group that does not detect the accident as the accident section.

  When the accident current in the power distribution system exceeds the switching capacity of the sensor built-in switch, the section dividing unit may divide the accident section after power supply from the distribution transformer is stopped.

  For example, in a one-phase, two-phase, three-phase ground fault in a grounded system, a two-phase, three-phase ground fault in a non-grounded system, or a two-phase, three-phase short-circuit accident common to both systems, the fault current is The switching capacity of the built-in switch may be exceeded. In such a case, in the present invention, the sending circuit breaker of the distribution substation is once opened, the power supply from the distribution transformer is stopped, and the sensor built-in switches before and after the accident section are opened. Since the management server has already identified the accident section at that time, the accident section can be divided without two power outages as in the conventional timed accident search and division method. The sensor built-in switch retains the previous on / off state even when power (power supply) is lost. For example, a latch mechanism (a device that mechanically grips the mechanism unit and maintains the switch state before power loss) ), And even after loss of power, the accident section is divided so that it can be opened and closed.

In order to solve the above-mentioned problems, a typical configuration of the accident search and division method according to the present invention includes a plurality of parallel lines that radiate from a distribution transformer and a connection line that connects the parallel lines. Arranged on the lines of the high-voltage distribution network, can be opened and closed and maintained in an open / closed state regardless of power loss due to an accident, and connected to a plurality of sensor built-in switches each equipped with a sensor for detecting the line state, A plurality of switch control devices including a switch control unit that acquires the sensor detection results and controls the sensor built-in switch sends the sensor detection results to a management server connected via a communication network for management. The server collects the sensor detection results through the switch control device, identifies the accident section based on the sensor detection results, and opens the built-in sensors on the power supply side and load side of the accident section. And dividing the fault section, further management server sends calculates the accident determination threshold in a plurality of sensor-equipped switches based on the type of line distance and line of distribution lines to a plurality of switches control device, the switching control section The presence or absence of an accident is determined by comparing the detection result with an accident determination threshold value .
In addition, another typical configuration of the accident search and division method according to the present invention is a high-voltage distribution network including a plurality of parallel lines radially branched from a distribution transformer and a connection line connecting the parallel lines. Is connected to a plurality of sensor built-in switches equipped with sensors that detect the line status, and can detect the detection results of the sensors. A plurality of switch control devices including a switch control unit that acquires and controls a sensor built-in switch transmits sensor detection results to a management server connected via a communication network. Collect the sensor detection results through the control device, identify the accident section based on the sensor detection results, open the sensor built-in switches on the power supply side and load side in the accident section, divide the accident section, and Management server periodically collects detection results plurality of switch control unit has acquired, and estimates a high probability of accidents occurring intervals.

  The above-described components based on the technical idea of the power distribution system and the description thereof can be applied to the accident search / division method.

  As described above, according to the power distribution system of the present invention, it can be applied to a multi-division multi-connection high-voltage distribution network. The section can be specified.

It is the power distribution system figure which showed the schematic structure of the power distribution system. It is explanatory drawing which showed the structure of the switch with a built-in sensor, and a switch control apparatus. It is the functional block diagram which showed the schematic function of the management server. It is a power distribution system diagram for demonstrating the identification process of the accident area of an accident area specific part. It is a power distribution system figure showing the state after an accident section was divided. It is explanatory drawing explaining the setting of the accident determination threshold value by a threshold value generation part. It is a power distribution system diagram explaining the division of the accident section when the switching capacity of the sensor built-in switch is exceeded. It is the flowchart which showed the flow of the process of the accident search and parting method. It is a power distribution system diagram for demonstrating the outline of the conventional timed type accident search method. It is a power distribution system diagram for demonstrating the outline of the conventional timed type accident search method. It is a power distribution system diagram for demonstrating the outline of the conventional distributed control type accident search method. It is a power distribution system diagram for demonstrating the outline of the conventional distributed control type accident search method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Distribution system 110 Distribution transformer 120 High voltage distribution network 130 Sensor built-in switch 140 Switch control device (RTU)
142 Detection Result Acquisition Unit 144 Open / Close Control Unit 150 Management Server 168 Information Collection Unit 170 Accident Section Identification Unit 172 Section Division Unit 174 Power Supply Restart Unit 176 Threshold Generation Unit 178 Accident Estimation Unit

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  When an accident occurs in a part of the power distribution system, the accident section where the accident occurred is identified, the front and rear sensor switches in the power distribution system are opened, and the power supply to the healthy sections other than the accident section is resumed. And the specific accident point in the accident section is specified. When a specific accident point is identified, the cause of the accident is quickly removed and normal power supply is resumed even in the accident section.

  The power distribution system of this embodiment can quickly and reliably identify such an accident section. Moreover, the power distribution system can prevent accidents by not only identifying accident sections but also predicting sections where accidents may occur. Hereinafter, a specific configuration of such a power distribution system will be described, and an accident search / partitioning method for specifying an accident point using the power distribution system will be described later.

(Distribution system 100)
FIG. 1 is a power distribution system diagram showing a schematic configuration of a power distribution system 100 according to the present embodiment. The distribution system 100 includes a distribution transformer 110, a high-voltage distribution network 120, a plurality of sensor built-in switches 130, and a plurality of switch control devices (RTU: Remote Terminal Unit, hereinafter simply referred to as RTU). 140 and a management server 150. In addition, here, in order to facilitate understanding, the distribution system is applied assuming an accident in a 6.6 kV distribution line.

  The distribution transformer 110 can change the secondary side voltage (sending voltage) while maintaining the energization state, such as a load ratio control transformer (LRT). It is a transformer.

  The high-voltage distribution network 120 includes a feeder that is a plurality of parallel lines branched from a distribution transformer and a connection line that connects the feeders in a mesh pattern. Therefore, depending on the open / closed state of the feeder-like switch and the connection-connected switch, a huge amount of combinations of the distribution systems can be formed. In the present embodiment, the accident section is appropriately specified for any combination of such distribution systems.

  The sensor built-in switch 130 is connected to the high-voltage distribution network 120 in a different arrangement (for example, A1, A2), and the line of the high-voltage distribution network 120 is opened and closed regardless of power loss due to an accident. Hold. This indicates that the sensor built-in switch 130 maintains the open / closed state immediately before the loss of power and can be opened / closed even after the loss of power. The sensor built-in switch 130 is arranged not only on the pillar but also on the ground and in the ground. In the present embodiment, the sensor built-in switch 130 incorporates a sensor.

  The sensor is one selected from the group consisting of a zero-phase current transformer (ZCT), a zero-phase voltage transformer (ZPD), a current transformer for each phase instrument (CT), and a current transformer for each phase instrument (PD) or Two or more combinations may be used. Therefore, a sensor can be comprised by the ground fault direction relay which consists of a combination of a zero phase current transformer (ZCT) and a zero phase voltage transformer (ZPD). Such a zero-phase voltage transformer (ZPD) can also be constituted by an instrument transformer (PD) for each phase. Moreover, you may use an instrument current transformer (CT) and an instrument transformer (PD) for an overcurrent relay or a voltage-current monitor.

  The zero-phase current transformer can identify a failure downstream (load side) from the sensor built-in switch, and the sensor built-in switch including the constant monitoring machine and control unit using the sensor itself. A defect or failure can also be identified. The management server can specify the section between the sensor group that detects the accident and the sensor group that does not detect the accident as the accident section.

  The sensor also detects line conditions such as voltage, current, zero-phase voltage, zero-phase current, harmonics, flicker, etc., and detects abnormal line conditions (decreased insulation level of covered wires and cables, tree contact, disconnection, High resistance ground fault). In this embodiment, the data transmission network between the RTUs 140 and between the RTU 140 and the management server 150 is formed by an optical cable. However, if a communication speed that does not hinder the identification and division of the accident can be realized, a metal cable or wireless communication is possible. Can also be used.

  In this embodiment, the sensor of the sensor built-in switch 130 is used as a sensor that is a target of data collection. However, the present invention is not limited to this, and a sensor built in any electrical device on the high-voltage distribution network 120 is used. Alternatively, a sensor device dedicated to data collection may be provided on the high-voltage distribution network 120.

  FIG. 2 is an explanatory diagram showing configurations of the sensor built-in switch 130 and the RTU 140. The sensor built-in switch 130 includes a zero-phase current transformer ZCT, a three-phase instrument current transformer CT, a three-phase instrument transformer PD, and a load switch LBS. Includes a detection result acquisition unit 142, an opening / closing control unit 144, a memory 146, and a transmission unit 148. The load switch LBS may be a circuit breaker CB capable of interrupting a larger accident current.

The zero-phase current transformer ZCT detects the zero-phase current I ₀ with a current transformer by utilizing the fact that the sum of the single-phase or three-phase currents is equal. The instrument current transformer CT measures the current of each phase, and the instrument transformer PD measures the voltage of each phase. The three-phase combination of the instrument transformer PD also functions as a zero-phase voltage transformer ZPD.

The zero phase voltage transformer ZPD detects the zero phase voltage and reacts only when a ground fault current flows in the line of the sensor built-in switch 130. When the line of the high-voltage distribution network 120 has a ground fault, a ground fault current I ₀ flows and a _zero- phase voltage V ₀ is generated in the line. For example, the zero-phase voltage at the time of complete ground fault (ground fault resistance = 0Ω) in a 6.6 kV line is 6,600 / √3 = 3,810V. As shown in FIG. 2, the zero-phase voltage transformer ZPD divides the generated zero-phase voltage to about several volts with a capacitor, and measures the voltage value. The switch control unit 144 determines whether there is an accident according to the zero-phase voltage V ₀ . The load switch LBS opens and closes the track in response to an open / close command from the open / close control unit 144.

  The detection result acquisition unit 142 acquires a detection result from a sensor built in the sensor built-in switch 130 and converts the detection result into data that can be recognized by the switching control unit 144.

  The opening / closing control unit 144 controls the sensor built-in switch 130 connected to the RTU 140 and opens / closes the load switch LBS. Moreover, when the accident determination threshold value mentioned later is obtained, the presence or absence of an accident can be independently determined by comparing the detection result acquired by the detection result acquisition unit 142 with the accident determination threshold value.

  The switching control unit 144 can also compare the accident current acquired from the detection result acquisition unit 142 with the switching capacity of the sensor built-in switch 130. 144 also includes that fact in the detection result. Such information indicating that the switch cannot be opened is referred to in order to eliminate unnecessary processing that the management server 150 attempts to open and close the sensor built-in switch 130.

  The memory 146 temporarily holds the detection result acquired by the detection result acquisition unit 142 or stores an accident determination threshold value.

  The transmission unit 148 transmits the detection result processed by the opening / closing control unit 144 to the management server 150, receives the opening / closing command of the load switch LBS from the management server 150, and transmits it to the opening / closing control unit 144. The open / close control unit 144 opens / closes the load switch LBS in response to the open / close command.

  The management server 150 is connected to the plurality of RTUs 140 via the communication network 122, and collectively monitors and controls the plurality of sensor built-in switches 130 via the RTU 140. The management server 150 assigns a unique identifier (address, etc.) to all the RTUs 140 in the distribution system 100, and changes the line status in the sensor built-in switch 130 and changes in the distribution system connection to the distribution system configuration database through the RTU 140. reflect. Further, when the presence or absence of an accident is grasped from the detection result from the RTU 140, the accident section is specified, and the sensor built-in switch 130 before and after the accident section is opened by remote operation through the RTU 140.

  Here, since the management server 150 centrally manages all the sensor built-in switches 130 of the high-voltage distribution network via the RTU 140, the accident section can be identified comprehensively. Further, by providing a sensor in each sensor built-in switch 130, it is possible to grasp the line conditions such as voltage, current, zero phase voltage, zero phase current, harmonics, flicker, etc. at the installation point of each sensor built in switch 130. It is possible to identify the accident section reliably.

  The management server 150 also performs protection coordination. The protection coordination aims to protect the healthy circuit by separating the accident section when an accident occurs in the high-voltage distribution network 120 and to continue supplying power to the healthy circuit while the protection functions cooperate with each other. .

  Further, in such a distribution system 100, the management server 150 uses the sensor detection results of each sensor built-in switch 130 to calculate the power flow, the bank sending current in the distribution transformer 110, and the secondary sending. It is also possible to calculate an appropriate settling value for a settling curve that is a function of voltage. Specific functions of the management server 150 are shown below.

(Management server 150)
FIG. 3 is a functional block diagram showing a schematic function of the management server 150. The management server 150 includes a server control unit 160, a memory 162, a display unit 164, an operation unit 166, and an information collection unit 168.

  The server control unit 160 manages and controls the entire management server 150 using a program stored in the memory 162 by a semiconductor integrated circuit including a central processing unit (CPU). In the present embodiment, the server control unit 160 also functions as an accident segment specifying unit 170, a segment dividing unit 172, a power supply restarting unit 174, a threshold value generating unit 176, and an accident estimation unit 178, which will be described later.

The memory 162 includes a ROM, a RAM, an E ² PROM, a nonvolatile RAM, a flash memory, an HDD, and the like, and stores a program processed by the server control unit 160, a distribution system configuration database, and the like.

  The display unit 164 is configured by a color or monochrome display, and can display system configuration information of the power distribution system stored in the memory 162 or detection results collected by the information collection unit 168 described later.

  The operation unit 166 includes a switch such as a keyboard, a cross key, and a joystick, and accepts a user operation input.

  The information collection unit 168 collects sensor detection results in the sensor built-in switch 130 via the RTU 140 and the communication network 122.

  The accident section identification unit 170 identifies an accident section based on the sensor detection results collected by the information collection unit 168.

  FIG. 4 is a power distribution system diagram for explaining the accident section specifying process of the accident section specifying unit 170. When the RTU 140 determines that an accident has occurred at an arbitrary point 180 downstream (load side) from the sensor built-in switch 130 connected to the RTU 140, the RTU 140 transmits the fact to the management server 150 via the RTU 140. Therefore, detection results indicating the presence of the accident are collected from all the RTUs 140 (here, RTUs connected to the sensor built-in switches A0 and A1) upstream from the accident point (power supply side).

  The accident section identification unit 170 compares the detection result with the distribution system configuration database stored in the memory 162, and among the RTUs 140 that issued the detection result, the sensor built-in switch A1 that is located farthest from the power source side, It is determined that there is an accident point 180 between the sensor built-in switch A2 that is downstream and closest thereto, and this is designated as an accident section 182.

  The section dividing unit 172 divides the accident section 182 by opening only the sensor built-in switches A1 and A2 before and after the accident section 182 specified by the accident section specifying section 170. Further, in order to continuously supply power to a healthy section downstream from the sensor built-in switch A2, the sensor built-in switch E in the connection path is closed via the RTU 140, and a closed circuit to the feeder A is formed.

  The power supply restarting unit 174 restarts power supply from the accident section 182 of the high-voltage distribution network 120 to the power source side and from the accident section 182 to the load side.

  FIG. 5 is a distribution system diagram showing a state after the accident section 182 is divided in this way. Here, the power of the distribution transformer 110 is directly supplied to the sound section from the sensor built-in switch A1 through the feeder A, and another feeder through the connection line E is connected to the sound section after the sensor built-in switch A2. The power from is supplied. Since the identification of the accident section 182 by the accident section identification unit 170 and the division of the accident section 182 by the section division unit 172 are performed at high speed, each sound can be transmitted without stopping the power supply from the distribution transformer 110 to the healthy section. Power supply to the section is continued.

  With this configuration, it is possible to quickly and appropriately respond to power supply to the load-side healthy section and load division of the high-voltage distribution network due to an accident. In addition, the sensor provided in the sensor built-in switch 130 can easily confirm that the power is stably supplied not only when the accident section is extracted but also as set after the accident.

  The threshold value generation unit 176 calculates an accident determination threshold value in the plurality of sensor built-in switches 130 based on the line distance between each of the plurality of sensor built-in switches 130 and the distribution transformer 110, and causes each of the RTUs 140 to correspond to each accident. A determination threshold value is transmitted. The RTU 140 may detect an accident by comparing the accident determination threshold received from the management server 130 with the measured value of the sensor built-in switch connected to the RTU 140 instead of or in addition to the above-described ground fault direction relay. Good.

  The threshold generation unit 176 refers to the distribution system configuration database, and determines a fixed impedance based on a distribution constant from the line distance or line type between each of the plurality of sensor built-in switches 130 and the distribution transformer 110 to the sensor built-in switch 130. The set value (current value or voltage value) to be detected by the RTU 140 that controls the sensor built-in switch 130 can be derived according to the load of the sensor built-in switch 130. Since the management server 150 calculates the accident determination threshold value so as to be larger than the set value in consideration of the load fluctuation, the RTU 140 indicates that an accident occurs when the current value or the voltage value exceeds the accident determination threshold value. Judgment can be made.

  FIG. 6 is an explanatory diagram illustrating the setting of the accident determination threshold value by the threshold value generation unit 176. In the impedance Z1 up to the sensor built-in switch A1 and the impedance Z1 + Z2 up to the sensor built-in switch A2 in FIG. 6, the current up to the sensor built-in switch A2 is larger, so the current value is larger in the sensor built-in switch A1. Become. Accordingly, the settling value of the current of the RTU 140 that controls the sensor built-in switches A1 and A2 is, for example, 550A and 520A. At this time, when the threshold value generation unit 176 sets the accident determination threshold value of the current of the RTU 140 that controls the sensor built-in switches A1 and A2 to 700A and 665A, the RTU 140 that controls the sensor built-in switches A1 and A2 The fact that an accident has occurred at the time when a current greater than the determination threshold is detected is transmitted to the management server 150 in the detection result.

  The accident determination based on such an accident determination threshold functions particularly effectively when the impedance from the power source is high and the accident current is small, and when no zero-phase voltage or zero-phase current is detected such as a short-circuit accident. .

  The accident estimation unit 178 periodically collects the detection results acquired by the plurality of RTUs 140, and estimates a section having a high probability that an accident will occur.

  In this embodiment, since the detection results from the sensors of the sensor built-in switch 130 are centrally managed through the RTU 140, a state where there is a high probability that an accident will occur although it has not resulted in an accident, for example, a decrease in the insulation level of a covered wire or cable It is possible to grasp tree contact, disconnection, high resistance ground fault, and the like. Therefore, it is possible to prevent an accident beforehand by not only specifying the accident section but also predicting the occurrence of the accident and dealing with the accident prediction section in advance.

  In addition, measurement information such as voltage, current, zero-phase voltage, zero-phase current, harmonics, flicker, etc. at each installation point of the sensor built-in switch 130 is measured in real time, so that the measurement information can be used to prevent accidents. Is possible.

  Further, when the fault current in the power distribution system 100 exceeds the switching capacity of the sensor built-in switch 130, the section dividing unit 172 may split the fault section after the power supply from the distribution transformer 110 is stopped. Good.

  FIG. 7 is a distribution system diagram illustrating the division of the accident section when the switching capacity of the sensor built-in switch 130 is exceeded. In the power distribution system 100, when a two-phase ground fault occurs at a predetermined position 180 of the high-voltage distribution network 120, the accident section identifying unit 170 of the present embodiment identifies the accident section 180, and the section dividing section 172 causes the accident. Divide the section. However, if such an accident is a one-phase, two-phase, three-phase ground fault in a grounded system, a two-phase, three-phase ground fault in a non-grounded system, or a two-phase, three-phase short-circuit accident common to both systems, the accident The current may exceed the switching capacity of the sensor built-in switch 130, and the sensor built-in switch 130 may not be able to divide the accident section.

  In this case, the accident current continues to flow through the feeder (A), and eventually, a protective relay such as an overcurrent protective relay or a ground fault direction relay of the distribution substation operates to open the sending circuit breaker CB1. Thus, power supply to the parallel line A of the high-voltage distribution network 120 is temporarily stopped. Here, the sensor built-in switches A0, A1, A2 have a latch mechanism that maintains the previous on / off state even when power (power supply) is lost, and the accident section is divided even after power is lost. Can be opened and closed. Therefore, as shown in FIG. 7, the closed states of the sensor built-in switches A0, A1, and A2 are maintained even after a power failure.

  According to the conventional timed accident search / division method, after the circuit breaker CB is opened, the switches A0, A1, and A2 are opened due to the loss of power, and then the switches with built-in sensors sequentially from the power source side. A0, A1, and A2 are turned on, and a power outage is forced again. In this embodiment, since the accident section has already been specified, only the sensor built-in switches A1 and A2 around the accident section 182 are opened via the RTU 140, and other sensor built-in switches 130 are turned on to supply power. Can be resumed immediately. Therefore, the accident section 182 can be quickly divided by only one power failure without involving two power failures as in the conventional timed accident search / division method.

  With the above-described power distribution system, an accident section can be identified at the same time as the accident occurs, and the accident section can be immediately removed by collectively controlling the sensor built-in switch 130. In addition, it is possible to minimize the power outage in the healthy section, and the influence of the power on the business establishments or homes can be minimized. Further, by centrally controlling each sensor built-in switch by one management server, even if it is applied to a power distribution system in which the system is switched every day, the effect is not lost.

(Accident search / division method)
Next, an accident search / division method for searching for an accident using the distribution system 100 described above will be described.

  FIG. 8 is a flowchart showing a process flow of the accident search / partition method. First, the threshold generation unit 176 of the management server 150 refers to the distribution system configuration database (S200), and a plurality of sensors based on the line distance and line type between each of the plurality of sensor built-in switches 130 and the distribution transformer 110. The accident determination threshold value in the built-in switch 130 is calculated (S202), and each accident determination threshold value is transmitted to the plurality of RTUs 140 (S204). The RTU 140 stores the accident determination threshold in the memory 146, and determines that an accident has occurred when the current value or the voltage value exceeds the accident determination threshold.

  When an accident occurs at an arbitrary position on the high-voltage distribution network 120, the RTU 140 that detects the accident transmits at least a detection result indicating the presence or absence of the accident to the management server 150. The management server 150 determines the presence or absence of an accident from the detection results collected by the information collection unit 168 (S210), and if it is understood that an accident has occurred, identifies the accident section based on the collected detection results (S212). Then, an attempt is made to open the sensor built-in switch 130 before and after the specified accident section (S214).

  At this time, when the accident current acquired from the sensor built-in switch 130 is compared with the switching capacity of the sensor built-in switch 130 on the RTU 140 side, it is known in advance that the electric circuit cannot be opened by the sensor built-in switch 130. The RTU 140 transmits the fact to the management server 150 together with the detection result. The management server 150 that has recognized the inability to open does not attempt to open (S214), and proceeds to the next step.

  Then, the management server 150 confirms whether or not the sensor built-in switch 130 has been opened (S216). If the accident current exceeds the switch capacity of the sensor built-in switch 130, or if the switch capacity is exceeded. If it is informed in advance from the RTU 140, that is, if the sensor built-in switch 130 cannot be opened, it waits for the sending circuit breaker in the distribution substation to be cut off according to the operation of the protective relay (S218), In the state where the power is cut off, only the sensor built-in switch 130 installed on the power supply side and the load side in the accident section is opened (the accident section is divided) (S220). When the sensor built-in switch 130 is ready, the delivery circuit breaker is turned on to resume power supply (S222). When the identification and division of such an accident section are completed, the distribution system configuration database is updated (S224), and the process from the beginning is repeated. If the sensor built-in switch 130 can be opened, the accident section is divided without shutting off the sending circuit breaker (S226).

  Further, in the determination of the presence or absence of an accident (S210), if the presence of an accident is not confirmed, an overload of the distribution system is determined from the detection result of each sensor built-in switch 130 (S230), and the management server 150 detects an overload. If it is determined that the load is present, the power distribution system is reconstructed (S232) to eliminate the overload. Then, the distribution system configuration database is updated (S224), and the processing from the beginning is repeated.

  Further, in the overload determination (S230), if the presence of the overload is not confirmed, the detection result is used to determine whether there is a highly likely section where an accident occurs (S240). When an insulation level drop, tree contact, disconnection, high resistance ground fault, etc. are grasped, the section is divided in the same manner as the accident section, and the accident prediction section is dealt with in advance (S242). In this way, accidents can be prevented. Then, the distribution system configuration database is updated (S224), and the processing from the beginning is repeated.

  By the accident search and division method described above, it is possible to quickly and surely identify the accident section, stably supply power to the healthy section, and to repair the accident section at an early stage.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  It should be noted that the steps in the accident search and division method of the present specification do not necessarily have to be processed in time series in the order described in the flowchart, and are executed in parallel or individually (for example, parallel processing or (Processing by object) may also be included.

  The present invention can be applied to a power distribution system for performing an accident search in a power distribution system and an accident search / division method.

Claims (4)

A distribution transformer;
A plurality of parallel lines radially branching from the distribution transformer, and a high-voltage distribution network including a connection line connecting the parallel lines;
A plurality of switches with built-in sensors, which are arranged on the lines of the high-voltage distribution network, can open and close the lines regardless of loss of power due to an accident, and have a sensor for detecting the line state;
A plurality of switch control devices each including a detection result acquisition unit that is connected to each of the plurality of sensor built-in switches and acquires a detection result of the sensor; and a switch control unit that controls the sensor built-in switch;
An information collection unit that is connected to the plurality of switch control devices via a communication network and collects detection results acquired by the switch control device, an accident zone specification unit that specifies an accident zone based on the detection results, In the section dividing unit that opens the sensor built-in switch on the power supply side and the load side in the accident section and divides the accident section , and in the plurality of sensor built-in switches based on the line distance and line type of the distribution line calculate the fault determination threshold and a management server that includes a threshold generating unit which transmits to said plurality of switch control unit,
The switching control section is characterized that you determine the presence or absence of an accident the switch controller detects obtains results by comparison of the accident determination threshold, the power distribution system system. A distribution transformer;
A plurality of parallel lines radially branching from the distribution transformer, and a high-voltage distribution network including a connection line connecting the parallel lines;
A plurality of switches with built-in sensors, which are arranged on the lines of the high-voltage distribution network, can open and close the lines regardless of loss of power due to an accident, and have a sensor for detecting the line state;
A plurality of switch control devices each including a detection result acquisition unit that is connected to each of the plurality of sensor built-in switches and acquires a detection result of the sensor; and a switch control unit that controls the sensor built-in switch;
An information collection unit that is connected to the plurality of switch control devices via a communication network and collects detection results acquired by the switch control device, an accident zone specification unit that specifies an accident zone based on the detection results, Open the sensor built-in switch on the power supply side and load side of the accident section and divide the accident section, and periodically collect the detection results obtained by the plurality of switch control devices. And a management server including an accident estimator that estimates a section with a high probability of occurrence of a power distribution system. Arranged on the line of the high-voltage distribution network consisting of a plurality of parallel lines that radiate from the distribution transformer and a connecting line that connects the parallel lines, and opens and closes the line regardless of power loss due to an accident. an openable and closable state holding and is connected to a plurality of sensor-equipped switches comprising a sensor for detecting the該線path state, acquires the detection result of the sensor, and opening and closing control for controlling the built-in sensor switch A plurality of switch control devices including a unit transmits a detection result of the sensor to a management server connected via a communication network,
The management server collects detection results of the sensors through the switch control device, identifies an accident section based on the detection results of the sensors, and includes the sensor built-in switches on the power supply side and load side of the accident section. Open and divide the accident section ,
Further, the management server calculates an accident determination threshold in the plurality of sensor built-in switches based on the line distance and the line type of the distribution line, and transmits to the plurality of switch control devices,
The accident search / partitioning method, wherein the open / close control unit determines the presence or absence of an accident by comparing the detection result with the accident determination threshold . Arranged on the line of the high-voltage distribution network consisting of a plurality of parallel lines that radiate from the distribution transformer and a connecting line that connects the parallel lines, and opens and closes the line regardless of power loss due to an accident. An open / close control unit that can hold an open / close state and is connected to a plurality of sensor built-in switches including a sensor that detects the line state, acquires a detection result of the sensor, and controls the sensor built-in switch A plurality of switch control devices including a sensor detection result transmitted to a management server connected via a communication network,
The management server collects detection results of the sensors through the switch control device, identifies an accident section based on the detection results of the sensors, and includes the sensor built-in switches on the power supply side and load side of the accident section. Open and divide the accident section,
Further, the management server, accidents search-cutting method, wherein the plurality of switch control unit detects obtains results periodically collects and estimates a high probability of accidents occurring intervals.

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